“As if?”
There isn’t any doubt about that...he is a case study of what happens to boxers who stick around too long.
I’ve often wondered which fight did the most damage. It was probably accumulated damage, though Larry Holmes really did a job on him.
I’m not a med person, but as an engineer, I think it’s like cumulative fatigue damage on a steel part.
All stress impacts above a “safe” level are additive.